Super Rugby semi-finals: Jacques Potgieter starts for Waratahs; Israel Folau returns

Waratahs head coach Michael Cheika has backed all three of his locks to play a decisive role in Saturday's Super Rugby semi-final against the Brumbies, despite dropping Will Skelton in favour of Jacques Potgieter.

Skelton has enjoyed a breakthrough season – rewarded with a Test debut against France - for the New South Wales franchise, but with a final four clash against their Australian conference rivals on the horizon Cheika has opted for the experienced Potgieter.

I'd love to start but whatever my role is in the team I'll try and provide impact. Cheik's harped on about it all year, when the bench comes on it's an impact thing, you've got to lift the intensity.

The hard-hitting former Springbok international will partner Kane Douglas in the second row in Sydney on Saturday as the Waratahs battle for the right to face either the Crusaders or Sharks in the final.

Despite giving the nod to Potgieter, Cheika believes the strains of the modern game demand much more from replacements and is backing 22-year-old Skelton to make a game-changing contribution from the bench.

"Rugby has changed so much, back in the day you'd have to be injured to be taken off. Now the replacement players are the matchwinners," the Waratahs coach said.

"So it's got a whole new scope about what happens and (Will) knows how important his role is."

Skelton has been earmarked a future star of Australian rugby after an impressive start to his career and despite being disappointed, the Auckland-born lock is eager to make his mark from the bench.

Impact

"Ah mate, that's footie," Skelton said. "I'd love to start but whatever my role is in the team I'll try and provide impact.

"If that's on the bench this week, I'll do my best for the team. Cheik's harped on about it all year, when the bench comes on it's an impact thing, you've got to lift the intensity."

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Wallaby full-back Israel Folau and winger Rob Horne both return to the side after missing the final match of the regular season against the Reds because of a thigh problem and flu respectively.

"I missed the last game against the Reds. The body's feeling fresh and I'm ready to go," said Folau, who has chalked up a competition-leading 12 tries in 12 games this season.

There will be no place among the replacements for Peter Betham, though, with Cheika feeling the winger needed more time at club level after 14 weeks out with a broken foot.

"He was giving me the daggers down there when I told him the team," said Cheika.

"I just think he needs to get a run under his belt, nothing can replace getting on the field and playing.”

Provisional Waratahs squad: 15 Folau, 14 Alofa, 13 Ashley-Cooper, 12 Beale, 11 Horne, 10 Foley, 9 Phipps, 1 Robinson, 2 Nau, 3 Kepu, 4 Potgieter, 5 Douglas, 6 Hoiles, 7 Hooper (capt), 8 Palu

Replacements (two to be omitted): 16 Latu, 17 Ryan, 18 Tilse, 19 Skelton, 20 Chapman, 21 McCutcheon, 22 McKibbin, 23 Naiyaravoro, 24 Carraro, 25 Crawford